On behalf of the Scientific Committee for Solar-Terrestrial Physics (SCOSTEP) I am pleased to welcome participants and guests to the thirteenth Solar-Terrestrial Physics Symposium (STP 13). SCOSTEP has been conducting these symposia for over 40 years to showcase important results obtained from the long-term international scientific programs run by SCOSTEP.

SCOSTEP is an interdisciplinary body of ICSU, the International Council for Science. The SCOSTEP Bureau is constituted by representatives from five international scientific unions, viz., IAGA, IAMAS, IAU, IUPAP, and URSI, and two ICSU interdisciplinary bodies, viz., COSPAR and SCAR. All these organizations have significant interest in solar-terrestrial relationship.

SCOSTEP completes the Climate and Weather of the Sun Earth System (CAWSES) program at the end of 2013 and launches its new scientific program known as the Variability of the Sun and Its Terrestrial Impact (VarSITI) in 2014. Therefore, the results presented in this symposium originate from both of these scientific programs. The number of data sources for solar-terrestrial research has also increased rapidly over the past few years, providing excellent data on the Sun, the interplanetary medium and the geospace. Results utilizing these data from space and ground also feature in the Symposium. Studies on the current strange state of the Sun are also reported in the Symposium. After a prolonged minimum period around 2009, the solar activity peaked at a level that is very low in the modern era. We have the opportunity to study the geospace and heliospheric consequences of a weak Sun. The CAWSES program covered the journey of the Sun toward the weak maximum in the 2012-2013 timeframe. The VarSITI program will study solar-terrestrial processes as the Sun enters into its declining activity phase. Tutorial presentations, keynote and review talks, and contributed papers and posters will form the basis for scientific deliberations during the meeting.

The Scientific Organizing Committee has put together an excellent program, helping disseminate the work done over the past several years. The Local Organizing Committee, under the leadership of Professor Chi Wang, has planned everything meticulously, so we all can focus on science and benefit from the deliberations. The local organizing committee has been instrumental in securing financial support to many young scientists. On behalf of SCOTEP, I would like to express my deepest gratitude to all the individuals in these committees for their tireless efforts.